Vitamin B12 Injection
Injection · 5 mg/mL methylcobalamin
- Bypasses gut absorption
- Supports energy and nerve health
- One vial lasts about ten weeks
Choose your plan
Why injectable B12?
B12 absorption depends on a specific mechanism in the gut that ageing, gut conditions and long-term metformin all interfere with. Injecting bypasses that entirely. It is worth being clear about what it does and does not do: correcting a genuine deficiency helps, but B12 is not a general energy treatment for people whose levels are already normal.
What to expect
- Bypasses the gut — The reason injection is used rather than a tablet.
- Pink urine is normal — The excess being excreted, nothing more.
- Weekly rhythm — One vial covers around ten weeks.
- Only helps a real deficiency — If levels are already normal, look elsewhere for fatigue.
How it works
Online consultation
Answer a few health questions — a licensed provider reviews online. No waiting rooms.
Prescription approved
Once approved, your medication ships discreetly to your door.
Feel the difference
Physician-guided support and check-ins keep results on track.
Dosing, safety & what's inside
Inject the prescribed dose subcutaneously or intramuscularly once weekly, or as directed
Vitamin B12 injection is FDA approved for B12 deficiency caused by poor absorption, including pernicious anemia. Using it for energy or weight is off-label.
Tell your care team straight away if you get trouble breathing, throat swelling or hives after an injection, vision changes, chest tightness or leg swelling, muscle weakness, or an irregular heartbeat.
Common side effects
- mild diarrhea
- itching
- rash
- a reaction where the injection was given
Rare but serious
- severe allergic reactions, which have been reported after injected B12
- low potassium and heart rhythm problems when severe anemia is treated quickly
- fluid on the lungs early in treatment
- rapid worsening of vision in people with an inherited eye condition called Leber's disease
Do not take this if you are sensitive to cobalt or to vitamin B12.
This is not a complete list of side effects. Message your care team about any symptom that worries you.
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Common questions
Who benefits from B12 injections?
People with genuinely low levels — often from age-related absorption changes, gut conditions, a plant-based diet, or long-term metformin use. If your levels are normal, more B12 is unlikely to change how you feel.
Why is my urine pink afterwards?
B12 is a deep red compound and the excess is excreted. Pink urine for a day or so is expected and harmless.
How often do I inject?
Typically weekly, though your clinician may set a different schedule. One 10 mL vial covers roughly ten weeks.
Can I take too much?
B12 is water-soluble and the excess is excreted rather than stored, so toxicity is not a practical concern.
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Built by a health team that's actually on your side
Prof Brian Kennedy, PhD
Globally recognized aging biologist and former CEO of the Buck Institute for Research on Aging, renowned for pioneering research on sirtuins, mTOR, and healthy aging.
Matt Kaeberlein
World-leading biogerontologist and Founding Director of the Healthy Aging & Longevity Research Institute, celebrated for uncovering the biological mechanisms of aging.
Rhonda Collins, FNP-C
Board-certified Family Nurse Practitioner with 15+ years of clinical experience, specializing in preventative wellness and biomarker-driven personalized care.